Working with Wire
When someone mentions the word wire, they are more than likely referring to a flexible, cylindrical piece of metal that can vary in size from just a few millimeters in diameter to several centimeters. Wire can refer to either a mechanical or electrical application. An example of a mechanical wire could be a Guy-wire, but this this guide will focus on electrical wiring.
Electrical wire is a backbone of our society. There is wire in houses to turn on lights, heat the stove, and even talk on the phone. Wire is used to allow current to flow from one place to another. Most wires have insulation surrounding the metallic core. An electrical insulator is a material whose internal electric charges do not flow freely and, therefore, does not conduct an electric current. A perfect insulator does not exist. However, some materials such as glass, paper, and Teflon, which have high resistivity, are very good electrical insulators. Insulation exists because touching a bare wire could allow current to flow through a person's body (bad) or into another wire unintentionally.
Here are some topics you might want to explore before reading about wire: